It is well known to prepare emulsions, in particular in the cosmetics and dermatological field, by means of hydrophilic-type nonionic surfactants obtained by grafting a polyoxyethylene chain. These emulsifying nonionic surfactants can be provided in the form of compositions based on alcohols, on acids or on fatty esters which have the advantage of being self-emulsifiable. "Self-emulsifiable" is understood to mean, in this instance, a composition which makes it possible to obtain a stable emulsion by simple mixing with an aqueous phase with moderate stirring.
The nonionic surfactants comprising a polyoxyethylene chain mentioned above have the disadvantage, however, of being irritating to a greater or lesser extent. Moreover, it was possible to find that the emulsions prepared with these self-emulsifying compositions were stable for only a relatively short period of time.
For the purpose of overcoming these disadvantages, the Applicant Company has provided, in Application WO-92/06778, for the use of self-emulsifiable compositions based on fatty alcohols and on alkylpolyglycosides or alkylpolysaccharides. Self-emulsifiable compositions as described in the abovementioned application are sold by the company S.E.P.P.I.C. under the tradename Montanov.RTM.68. The latter contain a mixture of alkylpolyglycosides, the fatty chains of which comprise 16 and 18 carbon atoms, and a mixture of fatty alcohols with the same fatty chain length.
The Applicant Company has, however, recently found that emulsifying compositions which are useful as self-emulsifiable compositions, of the Montanov.RTM.68 type, could result in emulsions being obtained which have little stability when they are subjected to low, indeed very low, temperatures, for example temperatures lower than approximately -20.degree. C. Some users of these emulsifying compositions want the emulsions which they prepare to be stable even at temperatures of this order.
Emulsifying compositions are consequently provided, by the present invention, which make it possible to obtain emulsions which are stable at low temperatures, for example temperatures of less than -20.degree. C. These emulsifying compositions, moreover, do not exhibit the disadvantage of the compositions based on polyoxyethylene compounds mentioned above. More particularly, these emulsifying compositions according to the invention are not irritating. In addition, the emulsifying compositions according to the invention can be used as self-emulsifiable compositions.